You are correct that they can't break the laws of thermodynamics, but they don't need to in order to have a workable business model. The reason is because you don't need it to result in more energy than you put in. You just need it to result in more revenue than input costs. This is practically possible because different energy forms have different costs and they're not all substitutable for each other. For instance, electricity may become a lot cheaper than liquid fuel, but you can't electrify a long range airliner, or most military equipment. So in a world where a watt of electricity can be bought for 1/3 the price of a watt of kerosene, using 2 units of electricity energy to make 1 unit of liquid fuel energy would be economical. (made up numbers, you get the point)